Apparatus and method for checking conditioning mode of a heat pump system

ABSTRACT

An apparatus for checking conditioning mode of a heat pump system includes: (a) a temperature sensing device coupled with the heat pump system at a sensing locus; (b) a comparing device coupled with the temperature sensing device and configured for comparing a first temperature sensed by the temperature sensing device at a first time with a second temperature sensed by the temperature sensing device at a second time to determine an extant conditioning mode; the extant conditioning mode being a first conditioning mode when the second temperature is greater than the first temperature; the extant conditioning mode being a second conditioning mode when the second temperature is less than the first temperature.

BACKGROUND OF THE INVENTION

The present invention is directed to heat pump systems, and especiallyto assuring proper operation of heat pump systems as directed by controldevices.

A heat pump system is essentially an air conditioning system that can beoperated in reverse. When it is desired that a conditioned indoor spacebe cooled, a reversing valve is oriented in a first position to causerefrigerant fluid to flow in a first direction. When refrigerant flowsin the first direction, an indoor coil operates as an evaporator,picking up heat from the conditioned space and removing it to an outdoorcoil. The outdoor coil operates as a condenser, losing heat to theatmosphere outside the conditioned space. When it is desired that theconditioned space be heated, the reversing valve is oriented in a secondposition to cause the refrigerant to flow in a second direction. Whenthe refrigerant flows in the second direction, the indoor coil operatesas a condenser, losing heat to the conditioned space. The outdoor coiloperates as an evaporator, picking up heat from the atmosphere andproviding the heat to the indoor conditioned space.

Movement of the reversing valve between the first position and thesecond position may be effected by any of several mechanisms. Magneticattraction to a first position or a second position is one common movingmechanism. Other mechanisms may include, by way of example and not byway of limitation, electrical solenoids, levers, bimetal expansionelements, and similar mechanisms for moving the reversing valve betweenits first and second positions.

There is a problem in operating the reversing valve in that the valvesometimes becomes stuck. The valve typically becomes stuck in its firstposition or in its second position, but may become stuck in an interimposition between its first and second positions. Whenever the reversingvalve is not in a proper position for effecting the operation ordered bya control device, the heat pump system operates incorrectly orinefficiently. For example, if a control device orders a heat pumpsystem to operate in a conditioning mode appropriate to cool a space andthe reversing valve does not move to the proper position to effectcooling operations, the heat pump system may actually be heating thespace instead of performing the ordered cooling operation. Similarly, ifa control device orders a heat pump system to operate in a conditioningmode appropriate to heat a space and the reversing valve does not moveto the proper position to effect heating operations, the heat pumpsystem may actually be cooling the space instead of performing theordered heating operation.

There is a need for an apparatus and method for checking conditioningmode of a heat pump system.

There is a need for an apparatus and method for checking conditioningmode of a heat pump system that can automatically cease operation of theheat pump system when the heat pump system is detected as being in aconditioning mode other than an ordered conditioning mode.

SUMMARY OF THE INVENTION

An apparatus for checking conditioning mode of a heat pump systemincludes: (a) a temperature sensing device coupled with the heat pumpsystem at a sensing locus; (b) a comparing device coupled with thetemperature sensing device and configured for comparing a firsttemperature sensed by the temperature sensing device at a first timewith a second temperature sensed by the temperature sensing device at asecond time to determine an extant conditioning mode; the extantconditioning mode being a first conditioning mode when the secondtemperature is greater than the first temperature; the extantconditioning mode being a second conditioning mode when the secondtemperature is less than the first temperature.

A method for checking conditioning mode of a heat pump system includesthe steps of: (a) in no particular order: (1) providing a temperaturesensing device coupled with the heat pump system at a sensing locus; and(2) providing a comparing device coupled with the temperature sensingdevice; and (b) sensing a first temperature by the temperature sensingdevice at a first time; (c) sensing a second temperature by thetemperature sensing device at a second time; (d) comparing the firsttemperature with the second temperature to determine an extantconditioning mode; (e) if the second temperature is greater than thefirst temperature then the extant conditioning mode is a firstconditioning mode; and (f) if the second temperature is less than thefirst temperature then the extant conditioning mode is a secondconditioning mode.

The method may include the further step of: (g) if the comparingindicates that the extant conditioning mode is not an orderedconditioning mode established by the heat pump system, ceasing operationof the heat pump system.

It is therefore an object of the present invention to provide anapparatus and method for checking conditioning mode of a heat pumpsystem.

It is a further object of the present invention to provide an apparatusand method for checking conditioning mode of a heat pump system that canautomatically cease operation of the heat pump system when the heat pumpsystem is detected as being in a conditioning mode other than an orderedconditioning mode.

Further objects and features of the present invention will be apparentfrom the following specification and claims when considered inconnection with the accompanying drawings, in which like elements arelabeled using like reference numerals in the various figures,illustrating the preferred embodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of a representative heat pump systememploying the apparatus of the present invention.

FIG. 2 is a flow diagram illustrating the method of the presentinvention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1 is a schematic diagram of a representative heat pump systememploying the apparatus of the present invention. In FIG. 1, a heat pumpsystem 10 is installed for conditioning an interior or inside space 12.A compressor 14 is situated in an exterior or outside space 17 outside awall 18. An interior or inside coil 20 is situated in interior space 12.Interior coil 12 is in fluid communication with an exterior or outsidecoil 22 and with compressor 14 in a fluid network involving a reversingvalve 24. Exterior coil 22 and reversing valve 24 are situated inexterior space 16. A blower unit 26 urges air across interior coil 20 ina direction indicated by an arrow 28. A blower unit 30 urges air acrossexterior coil 22 in a direction indicated by an arrow 32.

Heat pump system 10 also includes a thermostat unit 34 and a defrostunit 36 coupled with a control unit 38. Control unit 38 is also coupledwith compressor 14 and with reversing valve 24.

Reversing valve 24 has a common input port 40, a common output port 42and bidirectional ports 44, 46. A directing element 48 is situatedinside reversing valve 24. Directing element 48 may be situated in afirst position spanning common output port 42 and bidirectional port 44(indicated by a solid line) or in a second position spanning commonoutput port 42 and bidirectional port 46 (indicated by a dotted line).Details regarding how directing element 48 is moved are not illustratedin FIG. 1.

During cooling operations when heat pump system 10 operates to coolinterior space 12, directing element 48 is in its right-hand (dottedline) position in FIG. 1. In this configuration, refrigerant isexhausted from compressor exhaust 13 and enters reversing valve atcommon input port 40. Because directing element 48 is in its right-handposition bidirectional port 44 is left unmasked and refrigerant exitsreversing valve 24 via port 44. Refrigerant exits via port 44 and entersexterior coil 22 in a compressed vapor state. In the cooling operation,exterior coil 22 operates as a condenser and interior coil 20 operatesas an evaporator so that as refrigerant traverses exterior coil 22 it iscooled and condenses to a liquid. Air flowing over exterior coil 22because of blower unit 30 removes heat from refrigerant in exterior coil22. Liquid refrigerant enters interior coil 20 where it is heated by airforced over interior coil 20 by blower unit 26. In this mannerrefrigerant in interior coil 20 picks up heat from interior space 12thereby cooling interior space 12. Refrigerant exits interior coil 20 ina vapor state and enters reversing valve 24 via bidirectional port 46.Because directional element 48 is in a position spanning bidirectionalport 46 and output port 42, refrigerant entering reversing valve 24 viabidirectional port 46 is directed to exit reversing valve 24 via outputport 42. Thereafter refrigerant in its vapor state returns to compressor14 via an intake port 15.

During heating operations when heat pump system 10 operates to heatinterior space 12, directing element 48 is in its left-hand (solid line)position in FIG. 1. In this configuration, refrigerant is exhausted fromcompressor exhaust 13 and enters reversing valve at common input port40. Because directing element 48 is in its left-hand positionbidirectional port 46 is left unmasked and refrigerant exits reversingvalve 24 via port 46. Refrigerant exits via port 46 and enters interiorcoil 20 in a compressed vapor state. In the heating operation, interiorcoil 20 operates as a condenser and exterior coil 22 operates as anevaporator so that as refrigerant traverses interior coil 20 it iscooled and condenses to a liquid. Air flowing over interior coil 20because of blower unit 26 picks up heat given up by refrigerant ininterior coil 20 as the refrigerant condenses and cools. It is this heatthat warms interior space 12. Liquid refrigerant enters exterior coil 22from interior coil 20. In exterior coil 22 refrigerant is heated by airforced over exterior coil 22 by blower unit 30. In this mannerrefrigerant in exterior coil 22 picks up heat from exterior space 16thereby returning refrigerant in exterior coil 22 to a vapor state.Refrigerant exits exterior coil 22 in a vapor state and enters reversingvalve 24 via bidirectional port 44. Because directional element 48 is ina position spanning bidirectional port 44 and output port 42,refrigerant entering reversing valve 24 via bidirectional port 44 isdirected to exit reversing valve 24 via output port 42. Thereafterrefrigerant in its vapor state returns to compressor 14 via an intakeport 15.

One may observe that there are characteristic loci within heat pumpsystem 10 that exhibit temperatures related to the operation beingperformed by heat pump system 10. That is, when heat pump system 10 isperforming a cooling operation, temperatures at certain loci in heatpump system 10 will be relatively cool and other loci in heat pumpsystem 10 will be relatively warm. By way of example and not by way oflimitation, during cooling operations, heat pump system 10 will exhibitcool temperatures at port 23 of exterior coil 22, at port 19 of interiorcoil 20 and at bidirectional port 46 of reversing valve 24. Providing atemperature sensing device at one or more such characteristic locipermits one to check whether heat pump system 10 is actually performinga cooling operation. An illustration of placing a temperature sensingdevice according to the present invention is provided by placing atemperature sensing device 50 at bidirectional port 46. Temperaturesensing device 50 is coupled with control unit 38. This capability isparticularly useful in situations where, by way of example and not byway of limitation, control unit 38 (or another control input) ordersheat pump system 10 to cool interior space 12 but directional element 48malfunctions, such as by sticking or otherwise not completely moving toits proper location for cooling operations. In such circumstances, heatpump system 10 could be performing a heating operation in spite of itshaving been ordered to perform a cooling operation.

By way of further example and not by way of limitation, during heatingoperations, heat pump system 10 will exhibit warm temperatures at port23 of exterior coil 22, at port 19 of interior coil 20 and atbidirectional port 44 of reversing valve 24. Providing a temperaturesensing device at one or more such characteristic loci permits one tocheck whether heat pump system 10 is actually performing a heatingoperation. This capability is particularly useful in situations where,by way of example and not by way of limitation, control unit 38 (oranother control input) orders heat pump system 10 to heat interior space12 but directional element 48 malfunctions, such as by sticking orotherwise not completely moving to its proper location for heatingoperations. In such circumstances, heat pump system 10 could beperforming a cooling operation in spite of its having been ordered toperform a heating operation.

Eventually an occupant of interior space 12 may notice that heat pumpsystem 10 is not performing an ordered operation—heating or cooling.However it would be better if heat pump system 10 could itself noteincorrect performance. It would be particularly advantageous if heatpump system 10 could take action, such as ceasing operation, as byshutting down compressor 14, in the event of noting incorrectperformance. Most heat pump systems have an installed defrost controlunit, such as defrost unit 36. Defrost units are typically configuredfor deciding when to cease compressor operation in response topredetermined system conditions. The system conditions that may occasiona compressor shut down vary from system to system. A capability torespond to certain circumstances of incorrect performance that may benoted by the present invention can be programmed into an existingdefrost control unit 36, thereby giving heat pump system 10 a capabilityto respond to noted occasions of incorrect performance without having toprovide an additional new feedback unit for implementing a compressorshut down. Simply reprogramming a defrost control device such as defrostcontrol unit 36 to accommodate effecting shut down on the occurrence ofadditional circumstances (e.g., incorrect performance other than orderedperformance) is an economical implementation of the preferred embodimentof the present invention. In such an embodiment, temperature sensingdevice 50 may be coupled directly with defrost unit 36 (not shown inFIG. 1).

Noting incorrect performance may be effected using a comparing device,preferably located in control unit 38 or in defrost unit 36, to comparetemperature sensed by a temperature sensing device at a characteristiclocus (an extant temperature) with an expected temperature that shouldoccur if heat pump system 10 is properly performing the orderedoperation. Improper performance may alternately be performed on atime-of-performance bases. Thus, by way of example and not by way oflimitation, if a temperature sensing device is placed for detectingtemperature of exterior coil 22 (or another appropriately situatedcharacteristic locus) one may compare temperature of exterior coil 22 ata steady state condition without compressor 14 operating withtemperature of exterior coil 22 at a steady state condition whilecompressor 14 is operating. If the off-compressor temperature is greaterthan the running compressor temperature, then it can be surmised thatthe unit is operating in a heating mode. If, in contrast, theoff-compressor temperature is less than the running compressortemperature, then it can be surmised that the unit is operating in acooling mode.

FIG. 2 is a flow diagram illustrating the method of the presentinvention. In FIG. 2, a method 100 for checking conditioning mode of aheat pump system begins at a START locus 102. Method 100 continues withthe step of, in no particular order: (1) providing a temperature sensingdevice coupled with the heat pump system at a sensing locus, asindicated by a block 104; and (2) providing a comparing device coupledwith the temperature sensing device, as indicated by a block 106.

Method 100 continues with the step of sensing a first temperature by thetemperature sensing device at a first time, as indicated by a block 108.Method 100 continues with the step of sensing a second temperature bythe temperature sensing device at a second time, as indicated by a block110. Method 100 continues with the step of comparing the firsttemperature with the second temperature to determine an extantconditioning mode, as indicated by a block 112. Method 100 continueswith the step of determining whether the second temperature is greaterthan the first temperature, as indicated by a query block 114. If thesecond temperature is greater than the first temperature, then method100 continues via YES response line 116 and the extant conditioning modeis a first conditioning mode, as indicated by a block 118. If the secondtemperature is less than the first temperature, then method 100continues via NO response line 120 and the extant conditioning mode is asecond conditioning mode, as indicated by a block 122.

Method 100 may (the verb “may” being indicated by a dotted line)continue with the step of determining whether the extant conditioningmode is an ordered conditioning mode established by the heat pumpsystem, as indicated by a query block 124. If the extant conditioningmode is an ordered conditioning mode, then method 100 continues via YESresponse line 126 to a locus 128, and method 100 continues thereafterexecuting steps indicated by blocks 108, 110, 112, 114, 118, 122, 124.If the extant conditioning mode is not an ordered conditioning mode,then method 100 continues via NO response line 130 and operation of theheat pump system is ceased, as indicated by a block 132. Method 100terminates as indicated by an END block 134.

Heat pump system 10 (FIG. 1) is an illustration of the preferredembodiment of the present invention. It is important to note that theapparatus and method of the present invention are useful in other heatpump systems, such as systems embodied in what are known in the industryas package units. Package units are heat pump units that have both coilslocated within a single housing that is situated outside the conditionedspace. The package unit is coupled with the conditioned space using airdirecting structures, such as air ducts.

It is to be understood that, while the detailed drawings and specificexamples given describe preferred embodiments of the invention, they arefor the purpose of illustration only, that the apparatus and method ofthe invention are not limited to the precise details and conditionsdisclosed and that various changes may be made therein without departingfrom the spirit of the invention which is defined by the followingclaims:

1. An apparatus for checking whether extant operation of a heat pumpsystem is an ordered operation directed by a control device coupled withsaid heat pump system; said heat pump system including a compressorcoupled with at least two fluid coils in fluid communication involving adirection-controlling valve; said ordered operation involving acharacteristic systemic temperature range at a characteristic locus; theapparatus comprising: (a) a temperature sensing device coupled with saidheat pump system at said characteristic locus for determining a sensedsystemic temperature; and (b) a comparing device coupled with saidtemperature sensing device and with said heat pump system; saidcomparing device comparing said sensed systemic temperature with saidcharacteristic systemic temperature range to effect said checking.
 2. Anapparatus for checking whether extant operation of a heat pump system isan ordered operation directed by a control device coupled with said heatpump system as recited in claim 1 wherein said at least two fluid coilsincludes an inside coil situated inside an enclosed space beingconditioned by said heat pump system, and an outside coil situatedoutside said space; said characteristic locus being at said outsidecoil.
 3. An apparatus for checking whether extant operation of a heatpump system is an ordered operation directed by a control device coupledwith said heat pump system as recited in claim 1 wherein saiddirection-controlling valve exhausting refrigerant through a first fluidport to said inside coil during heating operations; saiddirection-controlling valve exhausting refrigerant through a secondfluid port to said outside coil during cooling operations; saidcharacteristic locus being at at least one of said first fluid port andsaid second fluid port.
 4. An apparatus for checking whether extantoperation of a heat pump system is an ordered operation directed by acontrol device coupled with said heat pump system as recited in claim 1wherein said heat pump system responds to said checking by ceasingoperation when said checking indicates said extant operation is not saidordered operation.
 5. An apparatus for checking whether extant operationof a heat pump system is an ordered operation directed by a controldevice coupled with said heat pump system as recited in claim 2 whereinsaid heat pump system responds to said checking by ceasing operationwhen said checking indicates said extant operation is not said orderedoperation.
 6. An apparatus for checking whether extant operation of aheat pump system is an ordered operation directed by a control devicecoupled with said heat pump system as recited in claim 3 wherein saidheat pump system responds to said checking by ceasing operation whensaid checking indicates said extant operation is not said orderedoperation.
 7. An apparatus for checking conditioning mode of a heat pumpsystem; the apparatus comprising: (a) a temperature sensing devicecoupled with said heat pump system at a sensing locus; (b) a comparingdevice coupled with said temperature sensing device and configured forcomparing a first temperature sensed by said temperature sensing deviceat a first time with a second temperature sensed by said temperaturesensing device at a second time to determine an extant conditioningmode; said extant conditioning mode being a first said conditioning modewhen said second temperature is greater than said first temperature;said extant conditioning mode being a second said conditioning mode whensaid second temperature is less than said first temperature.
 8. Anapparatus for checking conditioning mode of a heat pump system asrecited in claim 7 wherein said heat pump system effects saidconditioning in an inside space and wherein said heat pump systemincludes a compressor coupled with at least an inside coil inside saidspace and an outside coil outside said space; said inside coil and saidoutside coil being in fluid communication involvingdirection-controlling valve; said sensing locus being at said outsidecoil.
 9. An apparatus for checking conditioning mode of a heat pumpsystem as recited in claim 7 wherein said heat pump system effects saidconditioning in an inside space and wherein said heat pump systemincludes a compressor coupled with at least an inside coil inside saidspace and an outside coil outside said space; said inside coil and saidoutside coil being in fluid communication involvingdirection-controlling valve; said direction-controlling valve exhaustingrefrigerant through a first fluid port to said inside coil duringheating conditioning operations; said direction-controlling valveexhausting refrigerant through a second fluid port to said outside coilduring cooling conditioning operations; said temperature sensing locusbeing at one of said first fluid port and said second fluid port.
 10. Anapparatus for checking conditioning mode of a heat pump system asrecited in claim 7 wherein said heat pump system establishes an orderedconditioning mode in response to direction from a control device coupledwith said heat pump system; said heat pump system ceasing operationswhen said comparing indicates that said extant conditioning mode is notsaid ordered conditioning mode.
 11. An apparatus for checkingconditioning mode of a heat pump system as recited in claim 8 whereinsaid heat pump system establishes an ordered conditioning mode inresponse to direction from a control device coupled with said heat pumpsystem; said heat pump system ceasing operations when said comparingindicates that said extant conditioning mode is not said orderedconditioning mode.
 12. An apparatus for checking conditioning mode of aheat pump system as recited in claim 9 wherein said heat pump systemestablishes an ordered conditioning mode in response to direction from acontrol device coupled with said heat pump system; said heat pump systemceasing operations when said comparing indicates that said extantconditioning mode is not said ordered conditioning mode.
 13. A methodfor checking conditioning mode of a heat pump system; the methodcomprising the steps of: (a) in no particular order: (1) providing atemperature sensing device coupled with said heat pump system at asensing locus; and (2) providing a comparing device coupled with saidtemperature sensing device; and (b) sensing a first temperature by saidtemperature sensing device at a first time; (c) sensing a secondtemperature by said temperature sensing device at a second time; (d)comparing said first temperature with said second temperature todetermine an extant conditioning mode; (e) if said second temperature isgreater than said first temperature then said extant conditioning modeis a first said conditioning mode; and (f) if said second temperature isless than said first temperature then said extant conditioning mode is asecond said conditioning mode.
 14. A method for checking conditioningmode of a heat pump system as recited in claim 13 wherein said heat pumpsystem effects said conditioning in an inside space and wherein saidheat pump system includes a compressor coupled with at least an insidecoil inside said space and an outside coil outside said space; saidinside coil and said outside coil being in fluid communication involvingdirection-controlling valve; said sensing locus being at said outsidecoil.
 15. A method for checking conditioning mode of a heat pump systemas recited in claim 13 wherein said heat pump system effects saidconditioning in an inside space and wherein said heat pump systemincludes a compressor coupled with at least an inside coil inside saidspace and an outside coil outside said space; said inside coil and saidoutside coil being in fluid communication involvingdirection-controlling valve; said direction-controlling valve exhaustingrefrigerant through a first fluid port to said inside coil duringheating conditioning operations; said direction-controlling valveexhausting refrigerant through a second fluid port to said outside coilduring cooling conditioning operations; said temperature sensing locusbeing at one of said first fluid port and said second fluid port.
 16. Amethod for checking conditioning mode of a heat pump system as recitedin claim 13 wherein the method comprises the further step of: (g) ifsaid comparing indicates that said extant conditioning mode is not anordered conditioning mode established by said heat pump system, ceasingoperation of said heat pump system.
 17. A method for checkingconditioning mode of a heat pump system as recited in claim 14 whereinthe method comprises the further step of: (g) if said comparingindicates that said extant conditioning mode is not an orderedconditioning mode established by said heat pump system, ceasingoperation of said heat pump system.
 18. A method for checkingconditioning mode of a heat pump system as recited in claim 15 whereinthe method comprises the further step of: (g) if said comparingindicates that said extant conditioning mode is not an orderedconditioning mode established by said heat pump system, ceasingoperation of said heat pump system.